SALISBURY — Four clusters of linked COVID-19 cases have surfaced in Rowan-Salisbury Schools.

This week, Landis Elementary and South Rowan High School were added to the state’s list of schools with active COVID-19 clusters. Landis has five staff members and two students who have tested positive. South has 13 students who have tested positive. There are also clusters at Southeast and Corriher-Lipe middle schools identified by RSS staff and not recorded on the state list yet. The district did not have final numbers for the clusters on Wednesday.

The latest reported clusters have already passed the number recorded during the 2020-2021 school year. In February, the district recorded its first cluster at Corriher-Lipe. Its second was at Granite Quarry Elementary School in May.

The state has not reported clusters in any schools or child care settings in the county outside of the district as of Tuesday.

Clusters are a minimum of five epidemiologically linked cases in a shared environment like a school. It means the cases were transmitted in a common location rather than five students in the same class contracting COVID-19 outside of the school.

District Marketing and Communication Director Tracey Lewis said all four schools are operating normally. The district follows guidance from the state toolkit on COVID-19 prevention and the Rowan County Health Department, Lewis said.

The district reviews positives and quarantines at schools every day, as well as the number of substitute teachers at each school. RSS administrators work with principals on appropriate staff-to-student ratios and has daily conversations with school nurses, as well as the Health Department, to confirm positives and advise quarantines.

Lewis said families at the schools and the Board of Education have been notified about the clusters.

During a Monday meeting, RSS administration told the board contact tracing and notifying families after infections is time consuming.

The board also mandated masks last week after quarantines and infections increased dramatically one week into the school year, doubling the district’s previous record high for quarantines. Unless the mandate is extended, it will expire after Aug. 31.

District officials expected quarantines and infections to continue to rise after the mandate because of the lag between exposure, infection and the appearance of symptoms.

The Centers for Disease Control and Prevention advises masks reduce the rate of COVID-19 transmission and mortality by capturing droplets containing viral material leaving the nose and mouth when everyone wears one.

Specifically, when children in a group are all wearing masks, the risk of transmission for COVID-19 is low. Students without a positive test do not have to quarantine if they were in contact with a COVID-positive student, wore a mask and the student who tested positive was also wearing a mask.

District-wide quarantine and infection numbers will be confirmed Friday afternoon, but the district reported 1,878 student quarantines and 94 student infections on Monday.